Add mboxreader plugin as submodule

Closes #641

.gitmodules

@@ -118,3 +118,6 @@
 [submodule "ace_editor"]
 	path = ace_editor
 	url = https://github.com/mothsART/ace_editor.git
+[submodule "mboxreader"]
+	path = pelican-mboxreader
+	url = https://github.com/TC01/pelican-mboxreader

Readme.rst

@@ -132,6 +132,8 @@ Multi parts posts         Allows you to write multi-part posts
 
 Markdown Inline Extend    Enables you to add customize inline patterns to your markdown
 
+Mbox Reader               Generate articles automatically via email, given a path to a Unix mbox
+
 Neighbor articles         Adds ``next_article`` (newer) and ``prev_article`` (older) variables to the article's context
 
 Open graph                Generates Open Graph tags for your articles

pelican-mboxreader

@@ -0,0 +1 @@
+Subproject commit 2e3f9bef19fcc806dc022710aa214c360321f8e4